1. Statement of the Technical Field
The invention concerns control systems and methods for peer-to-peer control signal communications between controllers of at least two control systems (e.g., first and subsequent generation control systems) using an input/output (I/O) network of one of the control systems.
2. Background
Entities employing automation processes typically adopt automation process equipment and use the automation process equipment for many decades. This “conservative” aspect of the automation process industry is due to the significant expense incurred in setting up automation process equipment. In effect, a Process Automation System (PAS) typically contains at least two types of automation process equipment. The types of automation process equipment can include, but are not limited to, first generation automation process equipment and second (or subsequent) generation automation process equipment. Such a conventional PAS including first and second generation automation process equipment is shown in FIG. 1.
As shown in FIG. 1, the conventional PAS 100 includes at least one operator computer system 108, a first generation control system 102, a subsequent generation control system 118, and industrial equipment 116, 126. The first generation control system 102 is comprised of controllers 1041, . . . , 104N, input/output (I/O) networks 1141, . . . , 114N, and I/O processing modules (PMs) 1121, . . . , 112N. The I/O networks 1141, . . . , 114N are often Universal Asynchronous Receiver-Transmitter (UART) based networks. UART based networks are well known to those having ordinary skill in the art, and therefore will not be described herein. Likewise, the subsequent generation control system 118 is comprised of controllers 1221, . . . , 122N, I/O networks 1281, . . . , 128N, and I/O processing modules (PMs) 1241, . . . , 124N. The I/O networks 1281, . . . , 128N are often a Foundation Fieldbus® (FF) based networks. FF based networks are well known to those having ordinary skill in the art, and therefore will not be described herein.
The controllers 1041, . . . , 104N, 1221, . . . , 122N are configured to manipulate respective industrial equipment 116, 126. The industrial equipment 116, 126 can include, but is not limited to, motors, pumps, gauges, valves, transmitters, actuators, boilers, distiller units, and sensors. In this regard, it should be understood that each of the controllers 1041, . . . , 104N, 1221, . . . , 122N is communicatively coupled to the industrial equipment 116, 126 via a respective I/O network 1141, . . . , 114N, 1281, . . . , 128N and respective I/O PMs 1121, . . . , 112N, 1241, . . . , 124N. The phrase “I/O network” as used herein refers to a communications link between controllers and I/O PMs. The phrase “I/O processing module (or PM)” as used herein refers to an electronic device having digital and analog input and output terminals to which field signals are wired. Accordingly, each of the controllers 1041, . . . , 104N, 1221, . . . , 122N is communicatively coupled to the I/O PMs 1121, . . . , 112N, 1241, . . . , 124N via the respective I/O network 1141, . . . , 114N, 1281, . . . , 128N.
The I/O PMs 1121, . . . , 112N, 1241, . . . , 124N are configured to facilitate the transferring of data between the controllers 1041, . . . , 104N, 1221, . . . , 122N and the respective industrial equipment 116, 126. The I/O PMs 1121, . . . , 112N, 1241, . . . , 124N are also configured to process received data signals to place the same in a form suitable for use by a human and/or controller 1041, . . . , 104N, 1221, . . . , 122N. For example, if an I/O PM 1121 receives a four-to-twenty milliamp analog signal representing a temperature of a liquid contained in a tank, then the I/O PM 1121 converts the analog signal into useful data such as (1,000 degrees Celsius).
Each of the controllers 1041, . . . , 104N of the first generation control system 102 is communicatively coupled to the operator control system 108 and other controllers 1041, . . . , 104N via a common communications network 106. The common communications network 106 is typically a Universal Control Network (UCN). UCNs are well known to those having ordinary skill in the art, and therefore will not be described herein. The controllers 1041, . . . , 104N are coupled to each other via the common communications network 106 so that they can communicate process parameter information to each other. Such process parameter information typically includes temperature parameters, timing parameters, and liquid level parameters. This exchange of process parameter information is necessary for controlling an industrial process and equipment 116 in accordance with a particular control strategy.
Similarly, each of the controllers 1221, . . . , 122N of the subsequent generation control system 118 is communicatively coupled to the operator control system 108 and other controllers 1221, . . . , 122N via a common communications network 120. The common communications network 120 is typically an Ethernet Network. Ethernet Networks are well known to those having ordinary skill in the art, and therefore will not be described herein. The controllers 1221, . . . , 122N are coupled to each other via the common communications network 120 so that they can communicate process parameter information to each other. This exchange of process parameter information is necessary for properly controlling an industrial process and equipment 126.
Despite the cost saving advantage of a conventional PAS 100, it suffers from certain operational drawbacks. For example, the controllers 1041, . . . , 104N of the first generation control system 102 can not communicate process parameter information to the controllers 1221, . . . , 122N of the subsequent generation control system 118, and vise versa. One can appreciate that this inability to exchange process parameter information between the first generation controllers 1041, . . . , 104N and subsequent generation controllers 1221, . . . , 122N limits the integration of first generation and subsequent generation control equipment.
As such, there remains a need for an improved PAS that implements a cost effective approach for enabling communications between controllers of first generation and subsequent generation control systems.